It is necessary to form a pattern without a defect on a photomask used for the lithography process or on a template (original board) used for the imprint process in the manufacture of semiconductors. Thus, such a pattern defect is corrected when a photomask or a template is manufactured.
For example, in the process for manufacturing the photomask, a desired pattern is drawn on a resist film on a mask substrate, and the pattern is subsequently formed on the mask substrate by etching. After that, if a pattern defect is detected with a defect inspection apparatus, the detected pattern defect is corrected, for example, with a charged particle beam correction apparatus.
A defect caused by a film residue or under-etching on the desired pattern is referred to as a black defect. On the other hand, a defect caused by a film deficit or over-etching on the desired pattern is referred to as a white defect.
Techniques satisfying processing accuracy requirements have been established to correct of a pattern with a black defect. However, when a pattern with a white defect is corrected, it is difficult to form a desired pattern shape using the same material, as the substrate with a nanometer-scale accuracy.